Cognitive function in the locked-in syndrome.

OBJECTIVE: The lockedin syndrome (LIS) originates from a ventro-pontine lesion resulting in a complete quadraplegia and anarthria. Classically, communication remains possible by means of spared vertical eye movements and/or blinking. To allow assessing cognitive functions in LIS patients, we propose here a neuropsychological testing based on eye-coded communication. METHODS: Ten chronic LIS survivors were assessed 1 to 6 years after their brain insult. One patient was evaluated subacutely (at 2 months) and retested at 6 and 16 months. Neuropsychological testing encompassed short- and long-term memory, attention, executive functioning, phonological and semantic processing and verbal intelligence. RESULTS: None of the patients showed alterations in verbal intelligence. Impairments in one or several tests were found in five patients. In three of these patients, neuropsychological deficits could be related to additional cortical or thalamic structural brain lesions. In the other 2 patients, weakness or signs of fatigue only were observed in one or two cognitive tasks. Repeated measures in a subacute patient with pure brainstem lesion indicate the recovery of good levels of cognition 6 months after injury. CONCLUSION: Results indicate that LIS patients can recover intact cognitive levels in cases of pure brainstem lesions, and that additional brain injuries are most likely responsible for associated cognitive deficits in the LIS. Furthermore, a systematic neuropsychological assessment in LIS patients would allow detecting their cognitive deficits,which will contribute to improve their quality of life and of communication with family and medical caretakers.

The locked-in syndrome : what is it like to be conscious but paralyzed and voiceless?

The locked-in syndrome (pseudocoma) describes patients who are awake and conscious but selectively deefferented, i.e., have no means of producing speech, limb or facial movements. Acute ventral pontine lesions are its most common cause. People with such brainstem lesions often remain comatose for some days or weeks, needing artificial respiration and then gradually wake up, but remaining paralyzed and voiceless, superficially resembling patients in a vegetative state or akinetic mutism. In acute locked-in syndrome (LIS), eye-coded communication and evaluation of cognitive and emotional functioning is very limited because vigilance is fluctuating and eye movements may be inconsistent, very small, and easily exhausted. It has been shown that more than half of the time it is the family and not the physician who first realized that the patient was aware. Distressingly, recent studies reported that the diagnosis of LIS on average takes over 2.5 months. In some cases it took 4-6 years before aware and sensitive patients, locked in an immobile body, were recognized as being conscious. Once a LIS patient becomes medically stable, and given appropriate medical care, life expectancy increases to several decades. Even if the chances of good motor recovery are very limited, existing eye-controlled, computer-based communication technology currently allow the patient to control his environment, use a word processor coupled to a speech synthesizer, and access the worldwide net. Healthy individuals and medical professionals sometimes assume that the quality of life of an LIS patient is so poor that it is not worth living. On the contrary, chronic LIS patients typically self-report meaningful quality of life and their demand for euthanasia is surprisingly infrequent. Biased clinicians might provide less aggressive medical treatment and influence the family in inappropriate ways. It is important to stress that only the medically stabilized, informed LIS patient is competent to consent to or refuse life-sustaining treatment. Patients suffering from LIS should not be denied the right to die - and to die with dignity - but also, and more importantly, they should not be denied the right to live - and to live with dignity and the best possible revalidation, and pain and symptom management. In our opinion, there is an urgent need for a renewed ethical and medicolegal framework for our care of locked-in patients.

The locked-in syndrome: a syndrome looking for a therapy.

A review of the scientific literature on locked-in syndrome (LIS) is offered. The clinical features, diagnosis and prognosis of LIS are reviewed, and methods regarding the differential diagnosis of LIS with severe disorders of consciousness are considered. Effective treatment, physiotherapy, and methods of communication are reviewed. Although progress in the field of communication for patients with LIS is promising, it is concluded that there are new possibilities to be pursued and that a more positive outlook in the area of professional care of the patients, as well as more extensive imaginative research will facilitate new and positive strategies for this syndrome.

The locked-in syndrome: a syndrome looking for a therapy.

The locked-in syndrome (LIS) is a very severe condition caused by a primary vascular or traumatic injury to the brainstem, normally corresponding to a ventral pons lesion due to an obstruction of the basilar artery, and characterized by upper motor neuron quadriplegia, paralysis of lower cranial nerves, bilateral paresis of horizontal gaze and anarthria, and with preserved consciousness. Patients who have suffered this pontine lesion generally have preserved vertical eye movements and movement of the eyelids (blinking), this being their only means of responding to the outside world. A survey was conducted of 44 people diagnosed with LIS, all of them belonging to the Association of Locked-in Syndrome (ALIS) of France. Results of this survey showed that LIS was equally frequent in men and women (51.2% vs. 48.1%) and had occurred at any age between 22-77 years of age (normally between 41-52 years, the mean age being 46.79 years). The average time that transpired post-insult was 71.35 months. The principal cause of LIS was stroke (86.4%), with traumatic brain injury (TBI) being a distant second cause with an incidence of only 13.6%. The diagnosis of LIS was usually made around the middle of the second month after onset (mean of 78.76 days). The principal treatments, when present, were pharmacological and physiotherapy. However, 47.1% of the patients were not receiving treatment of any kind at the time of the survey. Neuropsychologically, 86% had a good attentional level, 97.6% were temporally oriented and 76.7% could read; 18.6% reported memory problems and 24% showed visual deficit (found mainly in patients with LIS originated by TBI); 47.5% reported a good mood state and 12.5% reported feeling depressed; 61.1% reported having sexual desire, but only 30% maintained sexual relations; 78% were capable of emitting sounds and 65.8% could communicate without technical aid; 73.2% enjoyed going out and 81% met with friends at least twice a month. Only 14.3% participated in social activities and 23.8% watched television regularly. Nearly 100% of the patients reported being sensitive to touch to any part of their bodies. This survey suggests diagnostics and rehabilitation procedures.